(1) Field of the Invention
The present invention relates to displays for facemasks. More particularly, the present invention relates to head-mounted displays worn by divers, firefighters, or the like.
(2) Description of the Prior Art
Divers, firefighters, first responders and other workers that wear facemasks frequently need to be apprised of environmental and status information for the successful and safe completion of their work assignments. Such information can include details of their surroundings, environmental and ambient conditions, and data regarding depth, orientation, or status of their life-support breathing apparatus.
Typically, this information has been provided by visual display screens. These display screens are generally integrated “displays-on-board” (IDOB) systems built directly into the sensor equipment, or remote head- or mask-mounted display systems attached to the sensor device via a cable. Both of the systems in use to date have significant shortfalls.
IDOB systems include flat panel or cathode ray tube screens built directly into the equipment or sensor held by the facemask wearer for displaying the data content of the equipment or sensor in a high-resolution format. However, such displays generally require a large amount of power, greatly limiting their use with the portable battery powered systems used in the aforementioned work environments.
Additionally, even small flat panel display screens have a minimum viewing distance of approximately 10-inches. At this distance, the screens may not be clearly visible when viewed in highly turbid or poor visibility environments, where the visibility may be in the range of one to two inches at best. Even in relatively clear conditions, the physical size and brightness levels required for viewing are a tactical hindrance for military operations requiring low probability of detection, such as clandestine or covert night missions.
Commercial off-the-shelf (COTS) head-mounted displays (HMDs) are available. However, the known displays typically require bulky interpupillary adjustment mechanisms for each individual user, and/or they have eye relief distances in the range of 25 mm. These features make them unsatisfactory for use with a facemask, since the entire display may not be seen.
Additionally, COTS HMDs generally use low resolution displays (on the order of 320×240 pixels, or 640×480 pixels), significantly reducing image quality and effectiveness. Also, a number of such systems have bulky mask attachment mechanisms and/or large mechanical housings making them extremely difficult to use and possibly causing a safety hazard.
Thus, a need has been recognized in the state of the art to provide systems for a facemask wearer to view high resolution, high data content, color imagery from a number of sensor devices. Further, a need exists to provide this imagery to the wearer regardless of ambient visibility conditions, and without requiring bulky optical adjustment mechanisms that may subject the facemask to leakage.